Prior Cancer in Patients with Ischemic Stroke: The Bergen NORSTROKE Study

Abstract

To compare the prevalence of prior or on-going cancer in patients with ischemic stroke and in the general population. We hypothesized that cardioembolic stroke is the most common stroke etiology in patients with prior cancer and that the outcome for ischemic stroke patients (ISP) with prior cancer is poor. All ISP registered in the Norwegian Stroke Research Registry (NORSTROKE) as part of the ongoing Bergen NORSTROKE Study were included. Stroke etiology was determined by the Trial of Org 10172 in Acute Stroke Treatment criteria, and the severity of the stroke was defined from the National Institutes of Health Stroke Scale score. Information about prior or ongoing cancer disease and type was retrospectively obtained from the medical patient record and The Cancer Registry of Norway. The prevalence of cancer among stroke patients was compared with the prevalence of cancer in the general population. Among 1456 ISP, 229 (15.7%) patients had 1 or more cancer diagnoses before the stroke. The prevalence of cancer was higher among stroke patients compared with the general population (P=.001). The most common cancer types were colorectal cancer (20.2%), prostate cancer (15.6%), breast cancer (12.7 %), cancer of the urinary tract system (10.3%), gynecological cancer (6.2%), and lung cancer (4.5%). Logistic regression analysis showed that patients with prior cancer had cardioembolic strokes at a higher rate (P=.03). The prevalence of prior cancer is higher in ISP than in the general population. ISPs with prior cancer are more prone to cardioembolism.